The invention relates to a print hammer for type printers, which is designed as a double-lever hammer. Such a double-lever hammer will be described both for the so-called inertia principle and the so-called ratio principle.
In known electro-magnetically operated print hammers the print hammer is designed as a single or a two-arm lever. Upon excitation of the electromagnet associated with the print hammer, this lever is attracted by the yoke of said magnet. During this, a print head arrangement at the end of the print hammer lever hits against a printing type to generate, via a ribbon, a type image on the paper arranged between print head and printing type.
Impact printers of this kind, in particular those used in connection with electronic data processing systems, require a very high printing capacity. Print hammers having a low mass and a correspondingly high acceleration and thus a high impact velocity at the moment of type printing fall short of this requirement. The higher the impact velocity, the less the risk of the printed image becoming slurred. However, in known print hammer arrangements an increase of the impact velocity is not possible without increasing the energy required for exciting the electromagnet associated with the print hammer. Therefore, it is the object of the invention to provide a print hammer which at constant excitation energy requirements of the electromagnet associated with this print hammer permits an increase in the impact velocity of the print head on the printing type.